Encapsulated aluminum-zirconium compositions

Abstract

Encapsulated aluminum-zirconium salt compositions are produced by combining and heating an aqueous aluminum- zirconium salt selected from aluminum-zirconium halohydrates and mixtures thereof; a hydrophobic liquid; and a carboxylate. The mixture is heated until substantially all of the free water has been removed. The encapsulated aluminum-zirconium salts precipitate out after the removal of the water. The encapsulated aluminum-zirconium salts are useful in deodorant and antiperspirant compositions.

What is claimed is: 
     
       1. An encapsulated aluminum-zirconium salt comprising (I) an aluminum-zirconium halohydrate; contained in a shell comprising   (II) a carboxylate or mixture of carboxylates selected from carboxylates having the formula ##STR4## wherein R 1  is selected from the group consisting of a saturated alkyl group, unsaturated alkyl group, branched alkyl group, linear alkyl group consisting of at least 2 carbon atoms, a phenyl group, and a phenyl ethylene group; and Z is selected from the group consisting of the hydrogen atom, alkali metals, glyceryl and mixtures thereof.   
     
     
       2. A composition as claimed in claim 1 wherein the aluminum-zirconium halohydrate is an aluminum-zirconium chlorohydrate. 
     
     
       3. A composition as claimed in claim 1 wherein the carboxylate is stearic acid. 
     
     
       4. A composition as claimed in claim 1 wherein the carboxylate is stearic anhydride. 
     
     
       5. A composition as claimed in claim 1 wherein the carboxylate is stearoyl chloride. 
     
     
       6. A method for producing encapsulated aluminum-zirconium salt compositions comprising A) mixing together (i) an aluminum-zirconium halodydrate;   (ii) a non-water miscible hydrophobic liquid selected from the group consisting of low viscosity silicone fluids, paraffin oils, and mixtures thereof; and   (iii) a carboxylate selected from carboxylates having the formula ##STR5## wherein R 1  is selected from the group consisting of a saturated alkyl group, unsaturated alkyl group, branched alkyl group, linear alkyl group consisting of at least 2 carbon atoms, a phenyl group and a phenyl ethylene group; and Z is selected from the group consisting of the hydrogen atom, alkali metals, glyceryl and mixtures thereof;     (B) heating the mixture of (A) to remove substantially all free water; and   (C) recovering the encapsulated aluminum-zirconium salt.   
     
     
       7. A method as claimed in claim 6 wherein the aluminum-zirconium halohydrate is an aluminum-zirconium chlorohydrate. 
     
     
       8. A method as claimed in claim 6 wherein the hydrophobic liquid is a low viscosity silicones. 
     
     
       9. A method as claimed in claim 8 wherein the hydrophobic liquid is a cyclic low viscosity silicones having the formula ##STR6## wherein each R is independently selected from the group consisting of an alkyl group containing 1 to 30 carbon atoms and an aryl group containing 6 to 10 carbon atoms and x has the value of 3 to 10. 
     
     
       10. A method as claimed in claim 8 wherein the hydrophobic liquid is a linear low viscosity silicones having the formula ##STR7## wherein each R is independently selected from the group consisting of an alkyl group containing 1 to 30 carbon atoms and an aryl group containing 6 to 10 carbon atoms, R" is selected from the group consisting of R and a hydroxyl (--OH) group; and y has the value such that the viscosity of the silicone is less than 1,000 centistoke. 
     
     
       11. A method as claimed in claim 6 wherein the carboxylate is stearic acid. 
     
     
       12. A method as claimed in claim 6 wherein the carboxylate is stearic anhydride. 
     
     
       13. A method as claimed in claim 6 wherein the carboxylate is stearoyl chloride. 
     
     
       14. A method as claimed in claim 6 wherein the mixture is heated in step (B) to a temperature of between 100° C. and 150° C. 
     
     
       15. A method as claimed in claim 6 wherein the encapsulated aluminum-zirconium salts are recovered through filtration means. 
     
     
       16. A method as claimed in claim 6 wherein the process is controlled to produce an encapsulated aluminum-zirconium salt having a controlled particle size and shape.